Sen. Mark Kirk isn’t just distancing himself from the rest of the GOP — he’s fleeing from it.

From the Supreme Court vacancy battle to gay rights to criminal justice reform, the moderate Illinois Republican is sounding more like a Democrat with each passing day as he fights to save his political life in an overwhelmingly blue state this fall.

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Kirk is one of just two outliers in the Senate GOP Conference on whether the chamber should vote on Merrick Garland for the Supreme Court this year and has bent over backward to show he disagrees with his fellow Republicans. Aside from telling other Republicans to “man up” and vote on President Barack Obama’s nominee, Kirk has circulated memos to Republicans touting Garland and boasted about a personal note from Obama thanking Kirk for advocating for his nominee.

Just this week, Kirk co-sponsored a criminal justice reform bill that would loosen some mandatory minimum sentences, despite complaints within the GOP that it would unwittingly release violent criminals early from prison. And he joined with five of the most liberal senators to urge the NBA to move its 2017 All-Star Game out of Charlotte, North Carolina, in response to the state’s controversial new law that bans anti-discrimination protections for gay and transgender people.

Kirk’s strategy is dictated by his home state’s leftward bent: His Democratic challenger, Tammy Duckworth, may need to do little more than emphasize her party label to oust him in November. Kirk has long been considered the most endangered GOP incumbent in an awful year for Republican senators trying to get reelected. The party is defending 24 seats, and one of two divisive figures, Donald Trump or Ted Cruz, is likely to be leading its ticket.

“For me, it’s just Mark Kirk being Mark Kirk, because I was always very independent of my party in the House, as well as in the Senate,” Kirk, a former House member, said in an interview with Politico on Wednesday. “I think for Illinois, they want a thoughtful, independent voice and not just a party Xerox.”

There has been little public polling in the Illinois Senate race; the most recent was in July from the Democratic firm Public Policy Polling, and it showed Duckworth defeating Kirk, 42 percent to 36 percent. Though she faced an intraparty challenge from former Chicago Urban League CEO Andrea Zopp, Duckworth left the March primary mostly unscathed.

Kirk’s campaign released internal polling last week that showed him still losing to Duckworth, yet within the margin of error. The numbers from GS Strategy Group’s Greg Strimple showed Duckworth with 43 percent of the vote and Kirk with 40 percent, while 18 percent of those polled said they were undecided. Senate Democrats are confident they’ll win Illinois; nevertheless, the party’s campaign arm used Kirk’s internal numbers in a fundraising appeal Wednesday.

Kirk has lagged in the money chase, raising $1.2 million in the first quarter of 2016, compared with Duckworth’s $2.1 million haul. She had more than $4 million cash on hand as of the end of March, while Kirk had $3.3 million.

So the Republican is pulling out all the stops to showcase his independent streak — starting with the high-profile Supreme Court contretemps.

Only two GOP senators, Kirk and fellow moderate Sen. Susan Collins of Maine, are standing behind calls for hearings before November, and despite a slew of face-to-face meetings between Garland and Republicans, the White House is barely making a dent in the GOP blockade.

Kirk said he came away pleased after meeting with Garland, but he stopped short of saying he would vote to confirm him. The judge is a Chicago area native, and Kirk said Garland understood the issue of gang violence plaguing the city: “I could see via body language he definitely got it.”

Though Senate Majority Leader Mitch McConnell (R-Ky.) has wrangled the vast majority of his ranks in line with his no-hearings stance, Republican leaders have given Kirk significant leeway to distance himself — acknowledging he faces political headwinds like no other member of the GOP Conference.

“There’s plenty of room for individual senators to handle it the way they’re most comfortable,” Senate Majority Whip John Cornyn (R-Texas) said of Kirk’s outspokenness on the Supreme Court. “The basic point is, [Garland] is not going to be confirmed — nor should he, in my view. That’s the point; the rest is sort of incidental.”

Fellow Illinois Sen. Dick Durbin, the powerful second-ranking Senate Democrat, said “people have noticed” Kirk’s stance on the Supreme Court, and he said most voters back in the state agree with him.

“When he breaks from Mitch McConnell, it helps him,” Durbin said. “At the end of the day, though, he has chosen Mitch to be his leader.”

Other Democrats are crying foul over Kirk’s attempts to straddle the middle. On some issues, the Illinois senator has found himself ardently touting the GOP’s position: Last week, he bashed a fiduciary rule proposed by Obama that Democrats say puts clients’ needs ahead of financial advisers. And the hawkish Kirk was one of the loudest critics of Obama’s Iran nuclear deal, which Duckworth backs.

Democrats are also calling out Kirk’s past support for a controversial Medicare blueprint crafted by now-Speaker Paul Ryan and free trade policies. His opponents are also seizing on Kirk’s vow – most recently made in an interview with NBC Chicago – to back Trump if he becomes the GOP presidential nominee.

Yet Kirk said in the POLITICO interview Wednesday that Trump is a "riverboat gamble because I don’t know how he’ll turn out.”

"It’s remarkable that Republican Sen. Kirk’s self-styled independence never extends to giving middle-class and working families a break, but that’s the record," said Matt McGrath, a spokesman for the Duckworth campaign.

In an interview, National Republican Senatorial Committee Chairman Roger Wicker of Mississippi said Kirk has “always been able to run a suburban, maverick-type campaign,” dating back to his House days last decade. Republicans say his past couple of weeks of party-bucking is just the latest evidence of his nose for the political center.

“On choice, I’m different than the party. On gay rights, I’m different than the party,” Kirk said when asked whether he will continue to distance himself from the GOP this year. “From the first day I decided to run for the Congress, I endorsed the Employment Non-Discrimination Act. So it’s as old as I am in politics.”

Kirk consistently ranks as either the most or second-most vulnerable GOP senator, with his neighbor Ron Johnson of Wisconsin lumped next to him. But Kirk and Johnson couldn’t be handling the run-up to their elections more differently: Johnson has lined up with McConnell on the Supreme Court and declined to criticize party strategy.

“It’s a team sport. I try and support members of my team, who, by and large, we’re in agreement on a large percentage of the issues,” Johnson said in an interview. “I’m not really interested in busting up the team.”

But while the states may share a border and a Democratic tilt, they don’t share the same path to victory. Johnson must focus on turning out the same conservatives who’ve repeatedly elected Republican Gov. Scott Walker, while Kirk must concentrate more on luring centrists who disagree with the GOP’s opposition to gay marriage and moving the Supreme Court process forward.

He’s “doing exactly what he needs to be doing to solidify his independent brand in a heavily Democratic state,” said one national GOP strategist.

Further distancing himself from the rest of the GOP, Kirk has waded into issues that other Republicans aren’t too keen to get involved in. Asked about the attempt by Kirk and the Democrats to take the All-Star Game away from Charlotte, Sen. Richard Burr (R-N.C.) responded: “Oh, I’m not getting into that crap. Thanks.”